光学区直径与暗瞳直径的关系对不同程度近视患者SMILE术后视觉质量的影响

The effect of the relationship between the diameter of the optical zone and the diameter of the dark pupil on the visual quality of patients with different degrees of myopia after SMILE

目的观察飞秒激光小切口角膜基质透镜取出术(SMILE)后,光学区直径与暗瞳直径的关系对不同程度近视患者视觉质量的影响。方法回顾性分析2021年7月行SMILE手术矫治的近视及散光患者49例(96眼),18~35岁,平均(25.76±5.75)岁。依据手术光学区直径-暗瞳孔直径的差值分为3组:A组<0 mm(30眼)、B组0~1 mm(36眼)、C组>1 mm(30眼);各组内再依据术前等效球镜度(spherical equivalent refraction,SE)分为低中度近视组(<-6.00D)和高度近视组(≥-6.00D)。观察并且记录患者术前及术后3 mo裸眼视力(UCVA)、SE、角膜高阶像差、调制传递函数截止频率(MTFcutoff)、客观散射指数(OSI)、主观视觉质量问卷调查,其中角膜高阶像差包括角膜彗差、角膜球差及角膜总高阶像差。参数变化量用Δ表示,其计算方法为术后3mo参数数值-术前参数数值。结果术前基线三组间年龄、性别、UCVA、SE、角膜高阶像差、MTFcutoff、OSI及主观视觉质量等一般资料差异均无统计学意义(P>0.05),而光学区直径、暗瞳孔直径、光学区直径-暗瞳孔直径差异均有统计学意义(均P<0.01)。术后3个月三组间UCVA及SE差异亦均无统计学意义(均为P>0.05)。对于角膜彗差、球差及总高阶像差,三组间差异均具有统计学意义(均P<0.05),两两比较均发现A组高于B组和C组,差异均有统计学意义(均P<0.05)。三组内的角膜彗差、球差及总高阶像差均高于术前(均为P<0.05)。高度近视患者的Δ角膜球差组间的两两比较显示C高度近视组低于A高度近视组和B高度近视组,差异均具有统计学意义(P=0.045、0.047)。低中度近视患者的Δ角膜球差和Δ角膜总高阶像差组间的两两比较显示,A低中度近视组高于B低中度近视组,差异均具有统计学意义(P=0.003、0.006),B低中度近视组与C低中度近视组间差异均无统计学意义(P=0.464、0.962)。术后3个月时患者的MTFcutoff已经能恢复到术前水平(P>0.05),光学区直径与暗瞳孔直径差值小于0 mm时,术后3个月的散射指数较术前会有所增加(P=0.007)。A组手术前后的主观视觉质量评分差异无统计学意义(P>0.05),B组、C组术后的主观视觉质量评分[(7.53±3.81)分、(7.73±3.88)分]均低于术前[(9.75±4.05)、(11.00±6.35)分](P=0.002、0.003)。结论光学区直径大于暗瞳孔直径时,近视患者术后主观满意度明显提升,同时角膜彗差、角膜球差及角膜总高阶像差的增加均能相应减少;在此基础上,高度近视患者需要更大的光学区直径来减少术后角膜球差的增加。

Objective The objective of this study is to observe the effect of the relationship between the diameter of the optical zone and the diameter of the dark pupil on the visual quality of patients with different degrees of myopia after small incision lenticule extraction(SMILE).Methods A retrospective analysis was performed on 96 eyes from 49 myopic and astigmatic patients aged 18 to 35 years(average age of 25.76±5.75 years)who underwent SMILE surgery in our ophthalmology center in July 2021.Based on the difference between the diameter of the optical zone and the diameter of the dark pupil,they were divided into three groups:group A,<0 mm(30 eyes);group B,0–1 mm(36 eyes);and group C,>1 mm(30 eyes).Each group was then divided into mild to moderate myopic groups(<-6.00D)and high myopic groups(≥-6.00D)according to spherical equivalent refraction(SE).The patients’uncorrected visual acuity(UCVA),SE,high-order corneal aberration,modulation transfer function(MTF)cutoff,object scatter index(OSI),and responses to the subjective visual quality questionnaire were recorded before and 3 months after surgery.Parameter variation was represented byΔ,which was calculated by subtracting the preoperative parameter value from that obtained 3 months postoperatively.Results:Preoperative baseline optical zone diameter,dark pupil diameter,and their differences were statistically significant(all P<0.01),whereas age,sex,UCVA,SE,corneal higher-order aberration,MTF cutoff,OSI,and subjective visual quality were not statistically significant(all P>0.05).There were no significant differences in UCVA and SE between the three groups at 3 months after operation(all P>0.05),whereas significant differences were noted in the corneal coma,spherical aberration,and total higher-order aberration(all P<0.05).Pairwise comparisons showed that the values in group A was higher than those in groups B and C,and the differences were statistically significant(all P<0.05).Postoperative corneal aberration in all three groups were higher than that before surgery(all P<0.05).A pairwise comparison ofΔspherical aberration in patients with high myopia showed that the values of group C were lower than those of groups A and B,and the differences were statistically significant(P=0.045 and 0.047,respectively).A pairwise comparison ofΔspherical aberration andΔtotal high-order aberration in patients with mild to moderate myopia showed that the values of group A were higher than those of group B,with statistically significant differences(P=0.003 and 0.006,respectively),and no statistically significant differences were found between groups B and C(P=0.464 and 0.962,respectively).The patients’MTF cutoff values at 3 months after surgery were restored to the preoperative level(P>0.05).When the difference between the diameter of the optical zone and the diameter of the dark pupil was less than 0 mm,the OSI at 3 months after surgery was higher than that before surgery(P=0.007).The subjective visual quality scores of groups B and C after surgery(7.53±3.81 and 7.73±3.88,respectively)were lower than those before surgery(9.75±4.05 and 11.00±6.35,respectively)(P=0.002 and 0.003,respectively).Conclusion When the optical zone diameter was larger than the dark pupil diameter,the subjective satisfaction of myopia patients significantly improved,and the increase in comas,spherical aberration,and total high-order aberration decreased.On this basis,patients with high myopia require a larger optical zone diameter to reduce the increase in postoperative corneal spherical aberration.